JPH0378265B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal transfer recording device, particularly a color thermal transfer recording device.

First, FIG. 1 shows a general color thermal transfer recording apparatus.

In Fig. 1, 1 is a recording sheet, and supply roll 3
It is fed out from the rollers 2 ₁ to 2 _{4 and conveyed by roller pairs 2 1 to 2 4} . 4 ₁ , 4 ₂ , 4 ₃ are thermal transfer sheets coated with thermal transfer ink layers, and sheet 4 ₁ is cyan,
4 ₂ has a magenta thermal transfer ink layer, and 4 ₃ has a yellow thermal transfer ink layer. Each thermal transfer sheet is supplied by supply roll 5 ₁
~ 5 ₃ and wound up on winding rolls 6 ₁ ~ 6 ₃ . 7 ₁ , 7 ₂ , 7 ₃ are heat generating heads (thermal heads), and platen rollers 8 ₁ , 8
The recording sheet and the thermal transfer sheet are sandwiched between ₂ and 8 ₃ .

When performing color recording using the three colors, the head ₇₁ is first driven to thermally transfer and record the cyan color on the recording sheet 1, and then the cyan recorded sheet area is sent to the head ₇₂ where magenta is recorded. The color is thermally transferred and recorded over cyan ink,
Next, the sheet area where these two colors are recorded is head 7.
₃ , where the yellow color is further superimposed on the cyan and magenta inks and thermal transfer recording is performed. The sheet area on which recording has been completed is cut into a predetermined length by the cutter 9. In the above manner, when one head is being driven, the other two heads are at rest.

In the apparatus shown in FIG. 1, each of the thermal transfer sheets 4 ₁ to 4 ₃ is
When the storage rolls 6 ₁ - 6 ₃ are driven, the thermal transfer sheets 4 ₁ - 4 3 are wound up on these rolls, but when the rolls 6 ₁ - 6 ₃ are strongly driven, the conveyance of the thermal transfer sheets 4 ₁ - 4 ₃ is stopped.
4 ₃ is very thin, especially if the width is wide enough to cover B5, A4 size paper, etc.
To avoid instability, the contact portions with the heads 7 ₁ to 7 ₃ are configured to move due to the frictional force between them and the recording sheet 1 rather than the tensile force of the rolls 6 ₁ to 6 ₃ . has been done.

The device shown in FIG. 1 has the following problems.
In other words, the synchronized and close conveyance of the thermal transfer sheet and the recording sheet mainly relies on the frictional force between the two sheets at the contact portions with the heads 7 ₁ to 7 ₃ . The first point is that slippage is likely to occur between the two sheets when the force changes, and elongation or shrinkage stress caused by the heat applied by the heads 7 ₁ to 7 ₃ may cause wrinkles in the thin thermal transfer sheet. It is easy to cause this, and this is because the thermal transfer sheet
This problem becomes more noticeable as the size of the recording sheet becomes larger, such as covering large recording sheets such as B5 size and A4 size, and both of these deteriorate the quality of the recorded image. Also, head 7
Since the thermal transfer material of the thermal transfer sheet is heated and melted by _{the steps 1} to 7 ₃ and the two sheets are immediately separated, there is not enough time for the thermal transfer material to become familiar with the recording sheet, resulting in frequent transfer failures. For these reasons, it is not suitable for high-speed recording. In addition, in order to superimpose and transfer three colors without color misregistration, the positions of the three heads must be positioned with extremely high precision, which has the disadvantage that color misregistration is likely to occur due to device assembly errors. Furthermore, since three heads are arranged side by side, the device becomes large in size. Furthermore, when the paper is cut with a cutter after recording in three colors, the unused paper is inevitably pulled out to the cutter position, which is extremely wasteful.

The main object of the present invention is to provide a color thermal transfer recording apparatus with a simple structure capable of solving the various disadvantages mentioned above.

The embodiments described below include a cylindrical rotating body having a circumference longer than the length of a recording sheet, and positions that are close to or in contact with this rotating body and spaced apart from each other along the circumferential surface of this rotating body. and a heat application means for applying heat in a pattern corresponding to the recorded image information at a position between the entrance roller and the exit roller, and heat transfer material layer areas of different colors are applied to the sheet. Thin film sheets arranged in order in the conveyance direction are hung on the entrance roller, then wound along the circumferential surface of the rotating body and hung on the exit roller, and a recording sheet is sandwiched between the thin film sheets and the rotating body, The rotary body is rotated to convey the thin film sheet and the recording sheet in close contact with each other so as to pass through the thermal pattern application position, and the rotary body is repeatedly rotated to convey thermal transfer material of a different color with each rotation. A thermal transfer recording apparatus is characterized in that the image is thermally transferred onto the recording sheet by a corresponding signal.

Embodiments of the present invention will be described below with reference to the drawings.

Note that the embodiments described below include a cylindrical rotating body having a circumference longer than the length of the recording sheet, and a cylindrical rotating body that is in close proximity to or in contact with this rotating body, and that is arranged at positions spaced apart from each other along the circumferential surface of this rotating body. The sheet is provided with an inlet roller, an outlet roller, and a heat application means for applying heat in a pattern corresponding to the recorded image information at a position between the inlet roller and the outlet roller, and conveys sheets of thermal transfer material layer areas of different colors. Thin film sheets arranged in order in the direction are hung on the entrance roller, then wound along the circumferential surface of the rotating body and hung on the exit roller, and a recording sheet is sandwiched between the thin film sheet and the rotating body, The rotary body is rotated to convey the thin film sheet and the recording sheet in close contact with each other so as to pass through the heat pattern application position, and the rotary body is repeatedly rotated to transfer thermal transfer material of a different color with each rotation. The image is thermally transferred onto the recording sheet using a corresponding signal.

FIG. 2 is an explanatory diagram of one embodiment of the present invention. In FIG. 2, reference numeral 10 is a cylindrical platen drum in which a layer 12 of elastic material (preferably rubber) several millimeters thick is provided on the circumferential surface of a rigid drum 11 made of aluminum or the like. The circumference of the drum 10 is slightly longer than the length of the recording sheet. Reference numeral 13 denotes a rigid inlet roller disposed slightly apart from the circumferential surface of the platen drum 10;
4 is a rigid exit roller disposed slightly apart from the circumferential surface of the drum 10, and both rollers 13 and 14
are arranged parallel to the platen drum 10. As shown in the figure, the rollers 13 and 14 are spaced apart from each other in the normal rotation direction (described later) of the drum 10, and the circumferential length of the drum 12 in the normal drum rotation direction from rollers 13 to 14 is
It is longer than that from to 13. (In the figure, the former is about four times the latter.) 13' and 14' are rollers 1 and 1, respectively.
3 and 14, each of which is driven to rotate by frictional force. Guide rollers 15, 16, and 17 are provided parallel to the drum 10 so as to lightly contact the drum 10. The guide rollers 15 and 16 are rotated at the same circumferential speed as the drum 10. These drums 12, rollers 13, 14, 13', 1
It is preferable that the peripheral surfaces of 4'15, 16, and 17 are finished smoothly. S is a roll-shaped long thermal transfer sheet, which has a width equal to or wider than a wide recording sheet such as B5 or A4 size.
Thermal transfer sheet S is a solid transfer sheet that contains carnauba wax, ester wax, pigment, etc. as composition components and melts under heat at 60 to 90 degrees Celsius on a base film of 6 to 15 μm thick such as polyester film or capacitor paper. It is made by applying an ink layer to a thickness of approximately 5 μm. As shown in FIG. 4, the thermal transfer sheet S is made up of areas of three colors, yellow Y, magenta M, and cyan C, arranged in this order in the conveyance direction of the thermal transfer sheet S. Each of the areas Y, M, and C has the same length in the conveyance direction of the sheet S, and this length is equal to or slightly longer than the length of the recording sheet, and is equal to the circumference of the platen drum 10. Preferably, the length is equal to . In short, each of the regions Y, M, and C has a length and width that are longer than the length and width of the recording sheet, and each has an area that can sufficiently cover the recording sheet. Note that the length of the recording sheet or areas Y, M, and C refers to the length dimension in the conveyance direction, and the width refers to the dimension in the direction perpendicular to it. do.

The thermal transfer sheet S is unwound from the supply roll 18 on which it is wound, passed around the entrance roller 13 to change direction, wound around the platen drum 10, then passed around the exit roller 14 to change direction, and then taken up and rerolled. It is wrapped around 19. Guide rollers 15 and 16 lightly sandwich the thermal transfer sheet S between the rollers 13 and 14 and the drum 10, thereby ensuring movement of the sheet S without slipping or sagging. The thermal transfer sheet S is wound around the drum 10 so that the transfer ink layer faces the circumferential surface of the drum 10. Note that since the rollers 13 and 14 are slightly apart from the drum 10, the sheet S is suspended in the air for a short length between the roller 13 and the drum 10, and between the drum 10 and the roller 14 as shown in the figure.

Reference numeral 20 denotes a thermal head which has a large number of minute heating elements (for example, electric resistors) on its tip surface, and these large number of heating elements are arranged in a direction perpendicular to the direction of rotation of the drum 10. As is well known, the plurality of heating elements of the thermal head are selectively caused to generate heat by electric signals in accordance with recorded image information. The thermal head 20 is fixed to a support 21 that is rotatable about a shaft 22.
The support body 21 is pressed against the thermal transfer sheet S wrapped around the drum 10 by a spring 23 that elastically urges the support body 21 clockwise in the figure. That is, the distal end surface of the thermal head 20 on which the plurality of heating elements are arranged is brought into close contact with the back surface of the thermal transfer sheet S (the back surface of the surface on which the thermal transfer ink layer is located). Thus, the thermal transfer ink layer is heated from the back side of the sheet S by the thermal head 20 and is melted in a pattern corresponding to the recorded image. In order to uniformly bring the front end surface of the head 20 into close contact with the sheet S and to uniformly apply heat to the sheet S, the hardness of the rubber layer 12 is preferably about 30 to 35 degrees.

24 is a paper feed cassette that accommodates cut sheets of plain paper such as B5 and A4 sizes. A sheet (recording sheet) 25 in the cassette 24 is sent out by a paper feed roller 26 and reaches a timing roller pair 27. The timing roller pair 27 stops rotating until it is driven by a signal, which will be described later.
5 waits with its tip stopped by the roller pair 27 until the roller pair 27 is driven. When the roller pair 27 is driven, the sheet 25 starts moving, is guided by the guide plate 28, and enters between the platen drum 10 and the thermal transfer sheet S. The recording sheet 25 is closely held between the thermal transfer sheet S and the circumferential surface of the platen drum 10.
According to the rotation of the thermal transfer sheet S, the sheet is conveyed without slipping between the sheet and the thermal transfer sheet S.

Now, the rollers 13 and 14 and the platen drum 1
0 is rotated synchronously. An example of the drive mechanism is schematically shown in FIG. 29,3 in Figure 3
0 and 31 are platen drum 10 and drum 1, respectively.
3 and 14 are fixed rotating shafts. Gears 34 and 35 are connected to the shaft 29 via clutches 32 and 33, respectively.
is installed. Further, the shaft 29 is connected to a timing pulley 38 via clutches 36 and 37, respectively.
39 is attached. Above gear 34,3
5. The pulleys 38 and 39 are each fixed relative to the shaft 29 when the corresponding clutch is energized, and are free to rotate relative to the shaft 29 when the corresponding clutch is deenergized.

Gears 40 and 41 are fixed to the shaft 30,
The gear 40 connects to the gear 34 via an idler gear train 42.
The gear 41 is connected to the gear 35 via an idler gear train 43. Further, gears 44 and 45 are fixed to the shaft 31, and the gear 44 is connected to the gear 34 through an idler gear train 46, and the gear 45 is connected to the gear 34 through an idler gear train 46.
are respectively connected to the gear 35 via an idler gear train 47.

48 is a pulse motor, and a timing pulley 49 is fixed to its output shaft. Pulley 38,
A timing belt 50 is stretched between 49 and 49. Reference numeral 51 denotes a motor (which may be a DC motor, induction motor, etc.) that rotates in the opposite direction to the pulse motor 48, and a timing pulley 52 is fixed to its output shaft. A timing belt 53 is stretched between the pulleys 39 and 52.
Thus, the motor 51 moves toward the shaft 29 in a direction opposite to that caused by the motor 48 and at a higher speed than that caused by the motor 48.
It rotates.

Returning to FIG. 2, reference numeral 54 designates a signal plate fixedly protruding from the side surface of the drum 10. A well-known photocoupler is used in the path of the signal plate 54, which is composed of an emitter and a photoreceptor facing each other, and a signal plate is inserted between them so that the photoreceptor forms a signal by blocking the light from the emitter. 55 and 56 are arranged. Similarly, 57 is a signal plate fixedly protruding from the side surface of the drum 10, and photocouplers 58 and 59 similar to those described above are arranged in the passage of this signal plate 57.

In the above, when the print command switch (not shown) is closed, the paper feed roller 26 is activated to convey the recording sheet 25 to the timing roller 27 as described above. Meanwhile, pulse motor 48 of FIG. 3 is activated and clutches 32, 36 are energized.
As a result, pulley 49, belt 50, pulley 38
The drum 10 starts to rotate normally through the drum 10, and in synchronization with the drum 10, the roller 14 is rotated through the gear 34, the gear train 46, and the gear 44, and the roller 13 is rotated through the gear 34, the gear train 42, and the gear 40. starts rotating. Here, the gear ratios of the gears 34 and 40 are set such that the normal rotation (rotation in the direction of the arrow) circumferential speed of the roller 13 is slightly lower than the normal rotation (rotation in the direction of the arrow) circumferential speed of the drum 10. On the other hand, the gear ratio of the gears 34 and 44 is set such that the normal rotation circumferential speed of the roller 14 (rotation in the direction of the arrow) becomes the normal rotation circumferential speed of the drum 10. Therefore, thermal transfer sheet S
is in a tensioned state with no slack in the air-stretched portion between the roller 13 and the drum 10, and is conveyed by the roller 14 in synchronization with the drum 10 at the same speed. This increases the effect of wrinkle-free adhesion of the thermal transfer sheet S to the circumferential surface of the drum 10 and to the recording sheet. In the above example, roller 1 when the drum rotates forward
The circumferential speed of No. 4 was set to be the same as the circumferential speed of the drum 10, in order to convey the thin thermal transfer sheet without applying excessive force as much as possible. However, the circumferential speed of the roller 14 may be made slightly faster than the circumferential speed of the drum 10. In that case, the sheet S will be in a tensioned state at the air tension section between the roller 14 and the drum 10, which will prevent wrinkles in the thermal transfer sheet. Contributes to the adhesion effect to the recording sheet. In this way, it is best to at least make the normal rotation peripheral speed of the roller 13 slightly slower than the normal rotation peripheral speed of the drum 10; The thermal transfer sheet S can also be placed between the entrance and exit rollers 13, 1.
4, the sheet S is wound while being pressed against the drum circumferential surface between both rollers, so the adhesion effect and wrinkle prevention effect of the sheet S to the drum circumferential surface and the recording sheet 25 are also improved compared to the conventional technology. It's extremely expensive. In any case, the thermal transfer sheet is pulled by the frictional force caused by the rotation of the roller 13 and is pulled by the roll 18.
It is fed out from the drum 10, pulled by the frictional force caused by the rotation of the roller 14, and fed out from the drum 10.
The material is rolled up by the rotation of the roll 19. The conveyance of the thermal transfer sheet between the rollers 13 and 14 is performed mainly by the frictional force between the drum circumferential surface and the recording sheet held between the drum circumferential surface and the recording sheet.

Now, as the drum 10 rotates forward, the signal plate 54
first reaches the photocoupler 55, and the timing roller 27 is driven by the signal obtained thereby. The timing roller 27 is the drum 10
The recording sheet 25 is conveyed at the same speed as the normal peripheral speed.
The recording sheet 25 is fed so that its leading edge coincides with the position directly above the leading edge of the signal plate 54 on the circumferential surface of the drum 10 in the radial direction of the drum (hereinafter referred to as the sheet leading edge alignment position). In other words, the rotational distance of the drum circumferential surface between the sheet leading edge alignment position on the drum circumferential surface at the time when the photocoupler 55 forms the signal and the position at which the thermal transfer sheet S and the drum circumferential surface start coming into close contact is determined by the timing. roller 2
7 and the recording sheet movement distance between the thermal transfer sheet S and the contact start position of the drum circumferential surface.

On the other hand, the thermal transfer sheet S has the areas Y, M, and C.
The leading ends of each sheet are set in the apparatus so as to be at a position on the circumferential surface of the drum 10 between the sheet leading edge alignment position and the sheet trailing edge alignment position described later, or to coincide with the sheet leading edge alignment position. In addition, the distance between the leading edges of adjacent areas Y, M, and C on the thermal transfer sheet S (in the sheet conveyance direction) is the distance between the leading edge of area Y and the leading edge of area M, The distance between the tip of M and the tip of region C is equal to the circumference of the drum 10. Therefore, thermal transfer sheet S
is conveyed so that the leading edges of the areas Y, M, and C are aligned with the same position on the circumferential surface of the drum 10 (for example, the sheet leading edge alignment position as described above) each time the drum 10 rotates. In other words, each region Y, M, C completely covers the recording sheet 25 each time the drum 10 rotates, and the recording sheet 25 protrudes beyond or behind each region Y, M, and C. Never.

In any case, the recording sheet 25 inserted between the thermal transfer sheet S and the circumferential surface of the drum 10 at the position where they start coming into close contact with each other is held tightly between them. The recording sheet 25 rotates together with the drum 10 and the thermal transfer sheet S and passes through the thermal head 20 due to the frictional force between the drum circumferential surface and the thermal transfer sheet. During the first rotation of the drum 10, the recording sheet 25 is aligned with the yellow color area Y of the thermal transfer sheet. When the leading edge of the recording sheet 25, in other words, the alignment position of the sheet leading edge on the drum circumferential surface reaches the position of the leading edge surface of the thermal head 20, the signal plate 54 is activated by the photo coupler 56.
The drive rotation of the thermal head 20 is energized by the signal obtained thereby. Thus, during the first rotation of the drum 10, the plurality of heating elements of the thermal head 20 generate heat in response to the recorded image yellow color information signal, and heat and melt the yellow color thermal transfer ink layer in the area Y of the thermal transfer sheet S. and adhere it to the recording sheet. In this way, the yellow color thermal transfer ink layer is adhered to the recording sheet in a pattern corresponding to the yellow color component of the recorded image. The forward rotation of the drum 10 is performed by the step motor as described above, and therefore the recording sheet and thermal transfer sheet integral with the drum 10 described above are also fed by step feeding, but the step feeding interval is determined as desired. It goes without saying that this is set in accordance with the recorded image resolution.

As the drum 10 is further rotated in the manner described above, the leading edge of the recording sheet will eventually reach the thermal transfer sheet S.
The distance between the drum 10 and the circumferential surface of the drum 10 is reached. Since the thermal transfer sheet S is rapidly rotated in direction by the roller 14 located near the separation start point, the recording sheet 25 is very easily separated from the thermal transfer sheet S by the force of its own waist. At this time, the ink layer that has been melted by the thermal head 20 and adhered to the recording sheet 25 peels off from the thermal transfer sheet S and remains on the recording sheet 25.

The recording sheet 25 that has come out from the separation starting point between the thermal transfer sheet S and the drum 10 is guided by the guide member 60, advances along the circumferential surface of the drum 10, and is held between the guide roller 17 and the drum 10. The roller 17 connects to the gear 3 via an idler gear (not shown).
4, and rotates in the opposite direction to the rotational direction of the drum 10 at a circumferential speed slightly higher than the circumferential speed of the drum 10. Therefore, after being separated from the thermal transfer sheet S, the leading edge of the recording sheet 25 is sent to the roller 17 in a state in which it is slightly lifted from the peripheral surface of the drum 10, but the roller 17 rotates at a peripheral speed slightly higher than that of the drum 10. As a result, the recording sheet 25 is brought into close contact with the drum circumferential surface again, and the leading edge of the sheet 25 is again accurately aligned with the sheet leading edge alignment position on the drum peripheral surface. In this way, the recording sheet 25 advances while being guided by the guide plate 62, and the thermal transfer sheet S
and is reinserted into the contact starting portion of the drum 10. During the second rotation of the drum 10, the recording sheet 2
5 is conveyed in alignment with the magenta color area M of the thermal transfer sheet S. Then, when the signal plate 54 comes to the position of the photocoupler 56 again and the photocoupler 56 forms a signal, this signal causes the thermal head 20 to
is started to be driven by the magenta color information signal of the recorded image, and as a result, magenta color ink is recorded on the recording sheet 25 overlapping the previously recorded yellow color ink.

This time as well, the recording sheet 25 separated from the thermal transfer sheet S as the drum 10 rotates is moved to the guide member 60.
The thermal transfer sheet S is guided to the drum 10 and the thermal transfer sheet S again with the leading edge aligned with the sheet leading edge alignment position on the circumferential surface of the drum 10 by the guide roller 17.
It is sent to the close contact starting section. and drum 10
During the third rotation, the recording sheet 25 is conveyed in alignment with the cyan-color area C of the thermal transfer sheet. Then, the signal board 54 is again connected to the photocoupler 56.
When the photocoupler 56 forms a signal at the position , this signal causes the thermal head 20 to start driving with the cyan color information signal of the recorded image. , cyan ink is further recorded over the magenta ink.

When the rear end of the recording sheet 25 has finished passing through at least the leading end of the guide member 20, and the leading end of the recording sheet 25 has not yet reached the leading end of the guiding member 20, for example, the drum 10 reaches the rotational position shown in FIG. When the signal board 57
9, and the rotary solenoid 61 connected to the guide member 60 is actuated by the signal from the photocoupler 59 at this time, causing the tip of the guide member 60 to come into contact with the circumferential surface of the drum 10 shown from the solid line position to the broken line in the figure. Rotate into position. The recording sheet 25 on which the three colors of ink have been thermally transferred is moved to the drum 1 by the guide member 60 which has been rotated to the position shown by the broken line.
0 and sent to a paper discharge roller 63. By the fourth rotation of the drum 10, the recording sheet on which the color image in the three colors has been recorded is conveyed via the paper discharge roller 63 and discharged onto the tray 64. When the recording sheet 25 is discharged onto the tray 64, the solenoid 61 is deenergized by the operation of the timer, and the guide member 60 returns to the solid line position in the figure.

On the other hand, the trailing edge of the recording sheet 25 is conveyed in a state that coincides with the position directly above the tip of the signal plate 57 in the drum radial direction on the circumferential surface of the drum 10 (hereinafter referred to as the sheet trailing edge alignment position). When the rear end of the recording sheet 25 passes through the starting point of separation between the thermal transfer sheet S and the drum 10, the signal plate 57 acts on the photo coupler 58, and the signal obtained thereby causes the clutch to be activated. 32,3
6. The step motor 48 is deenergized, the normal rotation of the drum 10 and the normal rotation of the rollers 13 and 14 as described above are stopped, and the feeding of the thermal transfer sheet S as described above is stopped. (The roller pair 63 rotates until the entire recording sheet is ejected onto the tray 64.) The signal from the photocoupler 58 is transmitted to the clutch 32,
36, the operation of the step motor 48 is stopped, and the clutches 33, 37 and the motor 51 are activated via a delay circuit with a short delay from the stop of the step motors 32, 36, 48. This clutch 33, 37,
Due to the operation of the motor 51, the drum 1 is rotated as described above.
0, rollers 13 and 14 rotate synchronously in the direction opposite to the arrow in FIG.
3 and 14 are rotated in the opposite direction at a higher speed than when using the step motor 48, respectively. As a result, the unused material (that is, the unused material that has not yet been melted by the head 20) that was fed out between the rear end alignment position of the recording sheet on the drum circumferential surface and the inlet roller 13 at the time when the photocoupler 58 formed the signal is removed. (No) Thermal transfer sheet S is
The drum is transported in the opposite direction to the normal rotation, and the roll 18
is rewound to. When the drum 10 reverses and returns to the angular position at the start of normal rotation (home position), the rear end of the signal plate 57 acts on the photocoupler 59 to form a signal, which causes the clutches 33, 37, Motor 51 is deenergized. That is,
The operation of rollers 13, 14 and drum 10 is stopped,
Rewinding of the sheet S is also stopped. When the drum 10 is rotated to eject the recording sheet on which the thermal head has completed its action, an unused thermal transfer sheet is fed out, but this unused sheet area is rewound again onto the roll 18 and used for the next recording sheet. It will be used for record sheets. By making the reverse rotation speed of the drum 10 and rollers 13, 14 faster than the normal rotation speed as described above, the above-mentioned rewinding time of the unused sheet is shortened, and the time until the recording process can be restarted is shortened. ing.

By the way, the gear 4 is set so that the circumferential speed of the roller 14 during the reverse rotation is slightly slower than the circumferential speed of the drum 10.
The gear ratios of the gears 41 and 35 are set so that the circumferential speed of the roller 13 during the reverse rotation is the same as the circumferential speed of the drum 10. As a result, the thermal transfer sheet S is stretched under tension in the air tension section between the roller 14 and the drum 10, and is conveyed in synchronization with the drum 10 without being subjected to excessive force by the roller 13. Therefore, the sheet S is rewound in a state in which it is in close contact with the drum 10 without wrinkles. Therefore, it becomes possible to more effectively eliminate the cause of wrinkles on the sheet S when the drum 10 is rotated normally again. Making the reverse circumferential speed of the roller 13 slightly faster than the reverse circumferential speed of the drum 10 also contributes to obtaining the above effect. In this way, it is best to at least make the reverse circumferential speed of the roller 14 slightly slower than the reverse circumferential speed of the drum 10;
Even if the reverse circumferential speed of 0 is the same, the thermal transfer sheet S is wrapped around the drum 10 while being pressed by the rollers 14 and 13, so although it is inferior to each of the above examples, the wrinkle prevention effect is sufficiently high. It is.

In addition, regardless of whether the rotation is forward or reverse, roller 1
In an embodiment where the circumferential speeds of 3 or 14 and the drum 10 are slightly different, if a tension force that forcibly pulls the thermal transfer sheet is generated between the roller and the drum,
Since the rollers 13 and 14 have smooth circumferential surfaces, slippage occurs between the rollers and the sheet, and this unreasonable force is released, thereby preventing damage and plastic deformation of the sheet.

Note that when the rollers 13, 14 and drum 10 are reversed as described above to rewind the unused thermal transfer sheet S, the solenoid 63' connected to the support plate 21 of the thermal head 20 is energized to resist the spring 23. rotate the head 20 counterclockwise, and
It is also preferable to separate it from the thermal transfer sheet to eliminate movement resistance against the sheet S and further reduce the cause of wrinkles.

The rolls 18 and 19 rotate in the direction of the arrow in the figure during recording and in the opposite direction when rewinding the sheet S, but roll 1 rotates the sheet S at a constant speed.
In order to unwind the thermal transfer sheet from 8 and wind it onto the roll 19, or vice versa, a friction drive roller mechanism is adopted which contacts the circumferential surface of the thermal transfer sheet wrapped around the rolls 18 and 19 and rotates it at a constant speed using frictional force. It's also good to do.

Further, in the above example, the rollers 13 and 14 are the drum 1.
The thermal transfer sheet was placed slightly apart from 0, and the thermal transfer sheet was stretched in the air for a short length between the roller 13 and the drum 10, and between the roller 14 and the drum 10.
One or both of the rollers 13 and 14 may be arranged so as to be lightly fused to the drum, and the thermal transfer sheet S and the stacked body of the thermal transfer sheet S and the recording sheet 25 may be sandwiched between the roller and the drum. good. This also provides a sufficiently high wrinkle prevention effect on the sheet S.

Further, in the above example, the driving timing of the roller 27, the driving timing of the head 20, the driving timing of the roller 13,
14. The forward rotation stop, reverse rotation drive timing, and reverse rotation stop timing of the drum 10 are controlled using a signal plate and a photocoupler. For example, clock pulses are counted using the time point when the signal plate 54 acts on the photocoupler 55 as a reference point. Each operation may be controlled by a microcomputer or the like. As this clock pulse, a pulse signal for driving the pulse motor can be used.

Further, in the above example, after the required number of thermal transfers are completed and the trailing edge of the recording sheet passes through the contact area between the thermal transfer sheet and the drum, the drum 10 and rollers 13 and 14 are reversed, and the unused portion of the thermal transfer sheet is transferred to the roller 1.
3, this is applied in a case where a cyan color area C is formed on the thermal transfer sheet S immediately following the yellow color area Y. However, as for the thermal transfer sheet S, following the yellow color area Y and before starting the cyan color area, there is a blank area (the length of which is only the base film) where no thermal transfer ink layer is provided.
When using a thermal transfer sheet having a circumferential length (preferably equal to or greater than 0), the above-mentioned reverse rotation of the rollers 13, 14 and drum 10 is not necessary.

In the above embodiment, a thermal head was used as a means for applying heat to the thermal transfer sheet, and the thermal head was brought into contact with the thermal transfer sheet, but it is also possible to apply heat using a laser beam as shown in Fig. 5. good. That is, in FIG. 5, 65 is a source (for example, a semiconductor laser) of the laser beam 66. Reference numeral 67 denotes a modulator (for example, an electro-optic device or an acousto-optic device) that modulates the laser beam 66 emitted from the beam source 65 in accordance with the recorded information signal of each color. The beam 66 modulated by the modulator 67 is scanned parallel to the axis of the drum 10 by a vibrating mirror (galvano mirror) 68, and is scanned parallel to the axis of the drum 10 by an fθ lens 69.
The light is focused onto the thermal transfer sheet S which is wound around. The laser beam 66 applies heat to the sheet S in a pattern corresponding to each color of recorded information signal.

Although FIG. 5 has the same configuration as FIG. 2 except for the heating means, in order to avoid complexity, illustrations of members and means that do not require particular explanation are omitted.

Although the above is an example in which thermal transfer ink layers of three colors are sequentially thermally transferred onto a recording sheet, the present invention can also be applied to an apparatus that thermally transfers thermal transfer ink layers of two colors or four or more colors onto a recording sheet in sequence. . Further, the present invention can also be applied to a transfer sheet having a heat sublimable transfer material layer.

In any case, according to the present invention, since the ink layer of the thermal transfer sheet is conveyed a long distance from the thermal head position to the separation position between the recording sheet and the thermal transfer sheet while being in close contact with the recording sheet 25, the thermal transfer sheet is The ink layer melted by this process fully re-solidifies in a state where it fully blends into the recording sheet and the previously thermally transferred ink layer. Therefore, the ink layer melted by the thermal head is
Nearly 100% of the information is transferred to the recording sheet, and there is virtually no omission of recorded information. Further, in the present invention, different colors are arranged in order in the conveyance direction of the cut-shaped recording sheet, and the area of the same color has a width that is approximately equal to the circumference of the rotating body and corresponds to the recordable width of the cut-shaped recording sheet. In devices using thermal transfer sheets with
Furthermore, slippage between the thermal transfer sheet, the rotating body, and the cut-shaped recording sheet can be effectively prevented, thereby preventing the occurrence of color misregistration. Furthermore, by rotating the rotating body multiple times in one direction, a different color can be recorded with each rotation, which improves the transfer efficiency, which makes it possible to obtain good color thermal transfer images. The invention greatly contributes to increasing the speed of color thermal transfer recording.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of a conventional thermal transfer recording device;
3 is an explanatory diagram of an example of the drive mechanism of the apparatus shown in FIG. 2, FIG. 4 is an explanatory diagram of a thermal transfer sheet, and FIG. 5 is an explanatory diagram of another embodiment of the present invention. FIG. 10 is a platen drum, 13 is an entrance roller, 1
4 is an exit roller, 20 is a thermal head, 25 is a recording sheet, 65 is a laser beam source, 68 is a vibrating mirror, and S is a thermal transfer sheet.

Claims (1)

[Scope of Claims] 1. A thermal transfer recording device that records on a cut-shaped recording sheet, comprising: a rotating body having a circumference longer than the length of the recording sheet to be recorded; and a rotating body provided along the circumferential surface of the rotating body. an inlet roller that is provided near or in contact with the circumferential surface of the rotating body and rotates at a circumferential rotational speed that is slower than the circumferential rotational speed of the rotating body; an exit roller that is provided in close proximity to or in contact with the rotating body and rotates at a rotational peripheral speed that is the same as or faster than the rotational peripheral speed of the rotary body, and different colors are sequentially arranged in the conveying direction of the recording sheet, The area of the same color is approximately equal to the circumferential length of the rotating body and has a width corresponding to the recordable width of the recording sheet stretched from the inlet roller through the circumferential surface of the rotating body to the outlet roller. a thermal transfer sheet; and a peeling member that is provided so as to be able to come into contact with and separate from the rotating body and peel off the recording sheet from the circumferential surface of the rotating body, and the rotating body is in a state where the recording sheet is held between the rotating body. A plurality of rotations are made in one direction, and each rotation transfers the thermal transfer material of a different color to the recording sheet according to the image information, color recording is performed on the recording sheet, and after the plurality of rotations, the A thermal transfer recording apparatus characterized in that the recording sheet is peeled off from the rotating body by a peeling member.